1. Field of the Invention
The present invention generally relates to a method and a system for searching images, in particular, to a method and a system for automatically searching images based on the identities or characteristics of figures.
2. Description of Related Art
Taking a picture has become very easy along with the widespread of digital cameras, and correspondingly, the number of pictures has been increasing dramatically. Accordingly, how to effectively manage a large number of pictures has become a major subject to users. Usually, when one wants to look for a picture from a large number of picture files, he/she has to recall the date on which the picture may be taken and browse through some folders in which the picture may be stored. If the pictures of a particular person are desired, these pictures could be found out according to the titles of the picture files and should be opened to check figures one by one, which is very time-consuming and troublesome.
A lot of picture management software has been provided to resolve foregoing problem, and they can be categorized into two types. In the first type of picture management software, a tag is added to each picture, wherein the tag records the related information of the picture such as date, place, equipment, event, or attendees. While searching for a picture, the picture is located by issuing a searching criterion such as the category, style, or attributes of the picture file. A method for searching and sorting media clips having associated style and attributes is disclosed in U.S. Pat. No. 6,970,859. FIG. 1 illustrates a media searching interface corresponding to the method. Referring to FIG. 1, a style identifier is associated with each media clip stored in a database based on a subjective evaluation of various characteristics of the media clip by an expert. While searching for a media file, a user can browse or search for the media file in the database based on a selected category, keyword, or style. However, in the method described above, all the pictures have to be tagged by the user manually, and every user has a different aspect about the content of the pictures. Thereby, foregoing method is too complicated and inefficient.
In the other type of picture management software, a desired picture is selected by directly comparing the low level characteristics of the picture, such as the colors and shapes of objects in the picture. An image query system and a method thereof are disclosed in U.S. Pat. No. 5,751,286. FIG. 2 illustrates a corresponding interface of the image query system. Referring to FIG. 2, images are searched in an image database according to the visual characteristics, such as colors, textures, shapes, and sizes, of the images. A user can give some example images for the invention to find images having similar visual characteristics as examples in the image database. However, in the case of searching for images of a particular person, low level characteristics have very weak relationship with human appearance. Therefore, user would take a lot of time looking for the image one by one from many undesired results. Thereby, the method described above is still not satisfactory.